os-ken/os_ken/app/simple_switch_snort.py

147 lines
4.9 KiB
Python

# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import print_function
import array
from os_ken.base import app_manager
from os_ken.controller import ofp_event
from os_ken.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
from os_ken.controller.handler import set_ev_cls
from os_ken.ofproto import ofproto_v1_3
from os_ken.lib.packet import packet
from os_ken.lib.packet import ethernet
from os_ken.lib.packet import ipv4
from os_ken.lib.packet import icmp
from os_ken.lib import snortlib
class SimpleSwitchSnort(app_manager.OSKenApp):
OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]
_CONTEXTS = {'snortlib': snortlib.SnortLib}
def __init__(self, *args, **kwargs):
super(SimpleSwitchSnort, self).__init__(*args, **kwargs)
self.snort = kwargs['snortlib']
self.snort_port = 3
self.mac_to_port = {}
socket_config = {'unixsock': True}
self.snort.set_config(socket_config)
self.snort.start_socket_server()
def packet_print(self, pkt):
pkt = packet.Packet(array.array('B', pkt))
eth = pkt.get_protocol(ethernet.ethernet)
_ipv4 = pkt.get_protocol(ipv4.ipv4)
_icmp = pkt.get_protocol(icmp.icmp)
if _icmp:
self.logger.info("%r", _icmp)
if _ipv4:
self.logger.info("%r", _ipv4)
if eth:
self.logger.info("%r", eth)
# for p in pkt.protocols:
# if hasattr(p, 'protocol_name') is False:
# break
# print('p: %s' % p.protocol_name)
@set_ev_cls(snortlib.EventAlert, MAIN_DISPATCHER)
def _dump_alert(self, ev):
msg = ev.msg
print('alertmsg: %s' % ''.join(msg.alertmsg))
self.packet_print(msg.pkt)
@set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
def switch_features_handler(self, ev):
datapath = ev.msg.datapath
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
# install table-miss flow entry
#
# We specify NO BUFFER to max_len of the output action due to
# OVS bug. At this moment, if we specify a lesser number, e.g.,
# 128, OVS will send Packet-In with invalid buffer_id and
# truncated packet data. In that case, we cannot output packets
# correctly.
match = parser.OFPMatch()
actions = [parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
ofproto.OFPCML_NO_BUFFER)]
self.add_flow(datapath, 0, match, actions)
def add_flow(self, datapath, priority, match, actions):
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
inst = [parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS,
actions)]
mod = parser.OFPFlowMod(datapath=datapath, priority=priority,
match=match, instructions=inst)
datapath.send_msg(mod)
@set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
def _packet_in_handler(self, ev):
msg = ev.msg
datapath = msg.datapath
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
in_port = msg.match['in_port']
pkt = packet.Packet(msg.data)
eth = pkt.get_protocols(ethernet.ethernet)[0]
dst = eth.dst
src = eth.src
dpid = datapath.id
self.mac_to_port.setdefault(dpid, {})
# self.logger.info("packet in %s %s %s %s", dpid, src, dst, in_port)
# learn a mac address to avoid FLOOD next time.
self.mac_to_port[dpid][src] = in_port
if dst in self.mac_to_port[dpid]:
out_port = self.mac_to_port[dpid][dst]
else:
out_port = ofproto.OFPP_FLOOD
actions = [parser.OFPActionOutput(out_port),
parser.OFPActionOutput(self.snort_port)]
# install a flow to avoid packet_in next time
if out_port != ofproto.OFPP_FLOOD:
match = parser.OFPMatch(in_port=in_port, eth_dst=dst)
self.add_flow(datapath, 1, match, actions)
data = None
if msg.buffer_id == ofproto.OFP_NO_BUFFER:
data = msg.data
out = parser.OFPPacketOut(datapath=datapath, buffer_id=msg.buffer_id,
in_port=in_port, actions=actions, data=data)
datapath.send_msg(out)